99 7.3 sputter, surge while running under load.

[mcgoo422000]

I have a 99 7.3 with 543,000 on it pulled some containers down to Florida this week. When I would get to running at highway speed sometimes I would develop for lack of better words a sputter, not a complete miss. The truck would loose some power and surge a little to. I have replaced the fuel filter and the supply pump had tank screens cleaned and reuglator spring done. Back a few months ago I replaced #2,8,3 and 5 injectors with New alliant ones. I notice when the sputter starts it surges a little at idle for a little while till it smooths out. Also I can detect the sputter while shifting when it starts. but the is no dead miss and the exhaust at tailpipe is smooth. I get no miss codes or bad injector codes. The only code I get is waste gate selenoid performance which I have had for years and exhaust backpressure valve performance P0476 , P1690. I also replaced the ebp sensor and checked tube. Can injectors fail inttermitently without coding up? I also notice it makes a crackle type noise when accellerating when it starts acting up.

[kaya@bernhausen]

how does it run cold? have you performed a buzz test?
what are the details as to why the fuel system was looked at?

[mcgoo422000]

Originally Posted by kaya@bernhausen

how does it run cold? have you performed a buzz test?
what are the details as to why the fuel system was looked at?

Fuel pressure was low 30psi. Screens weren't that birty in tank. Buzz test always passed even before Ireplaced the 4 bad injectors. It passes all the test in scanner last week before loading.

[kaya@bernhausen]

prolonged low fuel pressure can definitely cause injector damage.
the device you used, were you able to see injector per/del's?
and how does it run cold?

[mcgoo422000]

Originally Posted by kaya@bernhausen

prolonged low fuel pressure can definitely cause injector damage.
the device you used, were you able to see injector per/del's?
and how does it run cold?

It runs good cold I need a new GPR. It only acts up when warm and it quits if I cut it off after running a ways. Sure hope it's not the new injectors.
IT seems to be more noticable when I hold it steady go on a long straightaway.
Reminds me of an old 4 barrel qaudrejet when the back quads aren't right.

[timmyboy76]

Originally Posted by mcgoo422000

I have a 99 7.3 with 543,000 on it

Have you done the hutch mod? Ya, screens were cleaned, but could have clogged back up again. Simple mod, and have great conclussions.

[kaya@bernhausen]

Originally Posted by mcgoo422000

It runs good cold I need a new GPR. It only acts up when warm and it quits if I cut it off after running a ways. Sure hope it's not the new injectors.
IT seems to be more noticable when I hold it steady go on a long straightaway.
Reminds me of an old 4 barrel qaudrejet when the back quads aren't right.

hmm. i agree. this does sound an awful lot like a plugged screen.
i would install a vacuum gauge in line between the tank and the pump. if you read more than 3"/hg, you have a restriction